Effectiveness of protected areas in conserving migratory guanaco (Lama guanicoe) population in western Argentina

DI MARTINO S., WALKER S., NOVARO A., DIDIER K., DONADIO E., WURSTTEN A. Y PALACIOS R.; WALKER R.S.; NOVARO A.J.

Mendoza, Argentina

Congreso; Xth International Mammalogical Congress; 2009

CCT Mendoza, IADIZA, GiB, IFM, SAREM

Even large reserves are often not effective to protect highly mobile animals. The San Guillermo and Laguna Brava reserves in western Argentina encompass 1.4 million hectares and were created to protect a largely intact high-Andean ecosystem that includes as dominant herbivores perhaps the most abundant sympatric populations of vicuñas and guanacos in South America.  Both reserves are above 3,500 masl.  Vicuñas are mostly sedentary and occur within the limits of the reserves, but guanacos are presumed to be migratory and leave the reserves seasonally, though no accurate data are available. To assess guanaco movement patterns and the degree of protection provided by these reserves we studied seasonal distribution of guanacos using line transect counts at five altitudinal strata between 2,000 and 4,500 masl inside and in the vicinity of the reserves.  We surveyed 1888 km of transects on randomly selected sections of existing trails and counted 399 guanaco groups in 2007-9.  Throughout the year, 73% of guanacos counted occurred outside of the reserves, mostly at 3,000-3,500 masl, with 6.8 guanacos/km in winter and 1.6 guanacos/km in summer.  Guanacos at 2,000-2,500 masl were most abundant in winter and at 4,000-4,500 masl were most abundant in summer.  We are studying patterns of plant productivity and snow cover to determine factors that explain seasonal movements. Our data suggest that at least part of the population moves altitudinally throughout the year, and that most guanacos are not protected by these reserves, particularly in winter.  Measures should be taken to reduce poaching and limit competition from livestock in low areas.